Refrigerating apparatus



NOV 3, 1936. R GOULD REFRIGERATING APPARATUS Filed Jan. 25, 1936 INVENTOR. P 14:0 600.40.

. H1s- ATTORNEYS Patented Nov. 3, 1936 5 rue BEFRIGERATING APPARATUS Richard E. Gould, Dayton, Ohio, assignor to General Motors Corporation, Dayton, 01min, a corporation of Delaware Application January 25, 1936, Serial N... some 7 Claims. (011.257-2i6) l frig'erating system which will be of maximum efllciency and constructed so as to be of low frictional resistance to the flow therethrough of a refrigerating fluid.

Further objects and advantages of the present I invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing: Fig. l is a diagrammatic showing of a. refrigcrating system having a heat exchanger constructed according to the present invention incorporated therein;

Fig. 2 is an enlarged view partly in section and partly in elevation of a heat exchanger constructed according to the present invention;

Fig. 3 is a sectional view through the heat exchanger shown in Fig. 2 and taken on the line 3-3 thereof;

Fig. 4 is a fragmentary view showing the winding of a corrugated strip of metal upon a pipe or conduit forming part of the exchanger disclosed in Figs. 1 and 2; and

Fig. 5 is a fragmentary view of an edge portion of the corrugated metal strip shown in Fig. 4 and taken in the direction of the arrow 5 in Fig. 4.

In illustrating the present invention it is desired to point out that the efilciency of a refrigerating system is increased considerably when a heat exchanger is employed between the conduits which convey liquid refrigerant to and gaseous refrigerant from the evaporator or. cooling element of the system. In other words, when the low temperature of evaporated or gasifled refrigerant leaving the evaporator or cooling element of a refrigerating system can be utilized and transmitted to the relatively warm liquid refrigerant entering the evaporator, this liquid refrigerant is precooled and completely condensed prior to being admitted to the evaporator. Such precooling of the liquid refrigerant insures that when the expansion device or valve, which admits liquid refrigerant from the liquid refrigerant supply condull; to the evaporator opens, liquid refrigerant devoid of gas bubbles will enter the evaporator. The

precooling of the liquid refrigerant in the liquid refrigerant supply conduit also tends to reduce the pressure of the refrigerant in back of the expansion valve to thus insure proper functioning of the valve. These facts are well-known to those 5 skilled in the art and my invention is directed to the construction of an eflicient and practical heat exchanger for such use and which exchanger can be manufactured at low cost.

Referring to the drawing, for illustrating my invention, I have shown diagrammatically in Fig.

' 1 thereof a refrigerating system of the conventional compressor-condenser-expander type having my improved heat exchanger embodied therein. The refrigerating system includes a cooling 15 element or evaporator m mounted or positioned in a cabinet H, which cabinet in the present disclosure is of the room cooling type adapted to have air circulated through the cabinet and over the cooling element or evaporator to by a fan or blower Id through suitable openings 12 and I3 respectively provided in the walls of the cabinet. The cooling element or evaporator ill is connected with a compressor i5 of a refrigerant liquefying and circulating unit by a pipe or conduit is forming a continuation of conduit It. The compressor i5 is operatively connected, through suitable belt and pulley connections id, to an electric motor 2i. Operation of motor 2| and consequently compressor l5 causes the compressor to withdraw evaporated or gasified refrigerant from the evaporator l0. Compressor l5 compresses evaporated refrigerant and forwards same under pressure, through a pipe or conduit 22, to a condenser 23. Condenser 23 is cooled in any suitable and well-known manner to cause refrigerant therein to be condensed or liquefied. The liquid refrigerant flows from condenser 23 into a. receiver M where it is stored prior to being circulated, through a pipe or conduit 25, to the 40 evaporator It f'he liquid refrigerant pipe or conduit 25 extends through the-heat exchanger i1 and has an expansion valve or device 21 interposed therein at the point of connection thereto with evaporator iii. The expansion valve or device 21 is actuated under the control of a charge of volatile fluid contained in the thermostat bulb 28 and a pipe '29 which connects the bulb 28 with ally represented by the reference character 3|, and, preferably of the snap acting type, is interposed in the electric circuit leading to motor 2|,

and/or contraction of the bellows 32 for actuating the switch 3| to control the operations of motor 2| and consequently compressor l5.

Referring now to Fig. 2 of the drawingwherein an enlarged view of-the heat exchanger I1 is shown it will be noted that the construction of exchanger |'|v comprises a cylindrical or tubular member 35 having cap members 36 fitting over and sealed to the ends of member 35 as by soldering or welding same thereto. Cap member 36 is' provided with a flanged opening 31 which receives an end of the pipe I6 and an end of the pipe I 8 which provides an inlet and outlet for the chamber formed by the cylinder and cap members. Each of the cap or closure members 36 are also provided centrally thereto with a second flanged opening 38 through which the liquid refrigerant pipe or conduit 25 of the closed refrigerating system extends. It is to be understood that the refrigerant pipes |6, i8 and 25 are sealed within the flanged openings 31 and 38 of the cap members 36 in any suitable manner, such as by welding or soldering same thereto. Within the chamber formed by the cylinder 35 there is a fin structure, generally represented by the reference character 39, which may have portions thereof soldered in thermal contact with the conduit 25 and other portions thereof secured to the inner wall surface of cylinder 35 and which structure will be presently more fully described. Also located within the chamber formed by the cylinder 35 and the cap members 36 there are spider-like members 4|. One of the spider-like members 4| is positioned at each end of the fin structure 39. 'Each spider-like member 4| surrounds the pipe 25 and extends outwardly thereof so that a flange 42 formed thereon may engage and may be secured to the inner wall surface of the cylinder 35. The spider-like members 4| space the fin structure 39 from each of the cap members 36 to provide an unobstructed chamber or passage 43 at each end of the heat exchanger structure and are arranged to permit refrigerant entering the exchanger to flow through the openings 44 therein into any of the plurality of passages 45 (see Fig. 3) provided by the corrugated fin structure 33.

Referring now to Fig. 4 of the drawing I have disclosed therein a method of winding a continuous or one-piece corrugated strip of metal around the pipe or conduit 25 to provide the fin structure 33 of the heat exchanger It will be noted that the single continuous or one-piece strip of metal 5| is corrugated in any suitable and well-known manner withsmall portions 52 (see Fig. 5) extending parallel to relatively larger portions 53 and with straight portions 54 extending at right angles to and connecting the portions 52 and 53. The end portions of the corrugated strip of metal 5| are cut off at an angle to the extension of the strip to provide a straight or perpendicular portion at the ends where the winding of the corrugated strip 5| upon pipe or conduit 25 begins and ends. These straight cut-oi! portions match with and extend aoaaooa parallel to the extension of the cap members 33 in the structure disclosed in Fig. 2. The tube or conduit 25 may be rotated to cause winding of the corrugated metal strip thereon. After the strip 5| is wound around conduit 25 to the desired length the spider-like members 4| are placed over the conduit 25 and forced toward one another to press the edges of the spirally wound corrugated strip 5| into tight engagement. The corrugated metal strip 5| and the spider-like members 4| may then be sweated or soldered in any suitable manner to the conduit 25 to provide a rigid structure. The corrugated strip 5| and winding thereof upon conduit 25 is preferably carried out in a manner to cause registration of the portions 52, 53 and 54 of the strip 5| at the abutting edges thereof. This registration of the portions 52, 53 and 54 of strip 5| aligns the various corrugations throughout their extension within the heat exchanger I! and therebyprovides the plurality of unobstructed passages 45 extending longitudinally of the heat exchanger. It will be noted that the corrugated portions 54 of strip 5| are of such length as to extend continuously from the conduit 25 into contact with the inner wall surface of cylinder 35. When the cylinder 35 is placed over the fin structure 39 and its end members 4| the cylinder 35may, if desired, be soldered or otherwise secured to the corrugated portions 53 of the strip 5|. over the conduit 25 and soldered or otherwise secured to the cylinder 35 and conduit 25 to provide the completed sealed heat exchanger It will be apparent that I have provided an improved heat exchanger which can be manufactured at low cost and which is efficient for transferring the temperature of refrigerant in one part of a refrigerating system to another part thereof to permit the efllciency of the system to be increased. Relatively cold evaporated or gaseous refrigerant upon flowing from the evaporator l0 through conduit |6 enters the chamber 43 provided at one end of the exchanger ll. This refrigerant may be and is preferably broken up into a plurality of paths of flow by the spiderlike member 4| and may flow through any of the plurality of continuous longitudinally extending unobstructed passages 45 provided by the fin structure 39 in the exchanger H. The relatively warm liquid refrigerant flowing through conduit 25 of the refrigerating system gives up its heat to various portions of the fin structure 33 and this heat is carried away from the exchanger through the outlet end thereof or conduit i8. This transfer of heat between warm refrigerant and the relatively cold refrigerant in the refrigerating-system insures complete evaporation of refrigerant flowing from the evaporator to the compressor of the system and also increases the assurance that refrigerant flowing to the expansion valve or device 21 of the syste will be in liquid form. I

The heat exchanger is of an improved construction and the structure thereof which causes flow of refrigerant in a plurality of unobstructed paths, which paths are continuous and present a minimum of frictional resistance to the flow of refrigerant, through the exchanger provides a maximum of heat transfer. The improved fin structure is such that warm refrigerant flowing through the exchanger has ample opportunity to transfer its heat to the relatively cold refrigerant passing therethrough to thus increase the efficiency of a device of the type disclosed without The cap members 36 may then be placed materially increasing the cost of manufacture or production of such a device.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A heat exchanger for a refrigerating system comprising, means forming a chamber adapted to have a fluid circulated therethrough and provided with inlet and outlet openings for the fluid, a fluid conducting conduit extending through said chamber and being sealed to the walls thereof, and fln means contacting said conduit and extending outwardly therefrom into contacting engagement with said chamber walls, said fin means extending parallel to and in the path of flow of fluid to be circulated through the chamber.

2. A heat exchanger for a refrigerating system comprising, means forming a chamber adapted to have a fluid circulated therethrough and provided with inlet and outlet openings for the fluid, a. fluid conducting conduit extending through said chamber and being sealed to the walls thereof, a corrugated one-piece strip of metal spirally wound around and secured to said conduit, the corrugations of said strip ofmetal forming fins extending between said conduit and said chamber walls, and said fins extending parallel to and in the path of flow of fluid to be circulated through the chamber.

3. A heat exchanger for a refrigerating system comprising, means forming a chamber adapted to have a fluid circulated therethrough and provided with inlet and outlet openings for the fluid, a fluid conducting conduit extending through said chamber and being sealed to the walls thereof, a corrugated one-piece strip of metal spirally wound around and secured to said conduit, 2. spider-like member secured to said conduit at the ends of the corrugated metal strip and having a flange formed thereon for spacing the cor-= rugated metal strip from the end walls of the chamber, the corrugations of said strip of metal forming fins extending between said conduit and said chamber walls, and said flns extending parallel to and in the path of flow of fluid to be circulated through the chamber.

4. A heat exchanger for a refrigerating system comprising, a cylindrical member forming a chamber adapted to have a fluid circulated therethrough, a cap secured to each end of said cylindrical member for closing said chamber, each cap having an opening therein for providing said chamber with inlet and outlet openings at opposite ends thereof, a fluid conducting conduit extending through said chamber and being sealed to the capped ends thereof, and fin means contacting said conduit and extending outwardly therefrom into contacting engagement with said cylindrical chamber walls, said fin means extending parallel to and in the path of flow of fluid to be circulated through the chamher.

5. A heat exchanger for a refrigerating system comprising, a cylindrical member forming a chamber adapted to have a fluid circulated therethrough, a cap secured to each end of said cylindrical member for closing said chamber, each cap having an opening therein for providing said chamber with inletand outlet openings at opposite ends thereof, a fluid conducting conduit extending through said chamber and being sealed to the capped ends thereof, a corrugated one-piece strip of metal spirally wound around and secured to said conduit, the corrugations of said strip of metal forming flns extending between said conduit and said chamber walls, and said flns extending parallel to and in the path of flow of fluid to be circulated through the chamber.

6. A heat exchanger for a refrigerating system comprising, a cylindrical member forming a chamber adapted to have a fluid circulated therethrough, a cap secured to each end of said cylindrical member for closing said chamber, each cap having an opening therein for providing said chamber with inlet and outlet openings at opposite ends thereof, a fluid conducting conduit extending through said chamber and being sealed to the capped ends thereof, a corrugated One-piece strip of metal spirally wound around and secured to said conduit, a spider-like mem= ber secured to said conduit at the ends of the corrugated metal strip and having a flange formed thereon for spacing the corrugated metal strip from the cap end member of the chamber, the corrugations of said strip of metal forming a plurality of fins extending between said conduit and said chamber-walls, and said fins extending parallel to and in the path of flow of fluid to be circulated through the chamber.

7. A heat exchanger for a refrigerating system comprising, means forming an elongated chamber adapted to have a fluid circulated therethrough and provided with inlet and outlet-openings for the fluid, a fluid conducting conduit extending longitudinally through said elongated chamber and being sealed to the end walls thereof, a corrugated one-piece strip of metal spirally wound around and secured to said conduit, the

corrugations of said strip of metal in eachturn thereof around said conduit being in alignment RICHARD E. 

